Combustion of fuel in furnaces



June 9 1225.,

J. s. ATKINSON COMBUSTION 0F FUEL IN FURNACES Filed May 12, 1924 3 Sheets-Sheet l June 9', 1925.

J. s. ATKINSON COMBUSTION 0F FUEL IN FURNACES Filed May 12, 1924 3 Sheets-Sheet 2 Fig. 2

June 9, 1925.

J. S. ATKINSON comsusnon OF FUEL IN FURNACES Filed May 12, 1924 3 Sheets-Sheet 5 azkw d Patented June 9, 1925.

UNITED STATES I 1,541,613 PATENT, OFFICE.

JAMES STANLEY ATKINSON, or wnsrrriNsrnn, LONDON, ENGLAND, ASSIGNOR r socrn'rn ANONYME nus APPAREILS DE MANUTENTION & nouns STEIN, or PARIS,

FRANCE, A CORPORATION OF FRANCE.

COMBUSTION OF FUEL I1 Tv FURNACES.

Application filed May 12, 192 1, Serial No. 712,656.

To all whom it may concern. v

Be it known that I, JAMns STANLEY AT- KINSON, engineer, a subject of the King of Great Britain, residing at London, Great Britain, city of lvestminster, 47 Victoria Street, have invented certain new and useful Improvements in the Combustion of Fuel in Furnaces, of which the following is a specification.

This invention relates to the COlIlbUSiJlOn of fuel and it has for its object to provide improvements in or in connection with the hearths or fuel carriers by which the fuel is maintained, during combustion, in constant agitation and is also caused to travel between the point at which it is supplied and that at which it is discharged as ashes and clinker. r

V The invention has reference to the combustion of fuel in furnaces on hearths or fuel carriers consisting of endless travelling conveyors or belts. In furnaces with such hearths or fuel carriers as ordinarily constructed, the fuel travels with the conveyor or belt from one end of the furnace to, the other where it is discharged as ashes and clinker, the fuel during its travel being quiescent and not subject to agitation or movement other than that with the conveyor or belt. p A furnace for the combustion of fuel with a hearth or fuel carrier consisting of an endlesstravelling conveyor or belt has, .in accordance. with this I invention, the whole or a portion of the upper or. fuel bearing portion of the conveyor or belt extending from a lower to a higher level with the inclination or slope in the direction of move- A ment of the conveyor or belt and with-the points at which fuel is supplied to the conveyor or belt and-ashes and clinker are discharged therefromdisposed so that the fuel in its travel therebetween isisubjected to two influences, one being .due ,to the forward movement of the conveyor which lifts the fuel to a position at whichits angle of repose is exceeded, when it falls backward towards the lower level of the conveyor or belt, and the other being due togravity In order that the invention maybe clearly which causes the; fuel to move between the and readily understood, the embodiments thereof will 'now be described with reference to, and by the aid of, the accompanying drawings, on which Figure l is a longitudinal section on the line AB of Figure 2;

c Figure 2 isa transverse section through the furnace;

, Figure 3, a plan of the rear portion of the furnace;

'Figure 4, is a front end elevation, of a hearth orf-uel carrier and theair supply means according to one embodiment, and

Figure 5 shows a modified form of fuel carrier according toa second embodiment of the invention.

1 is the conveyor which is mounted on two parallel shafts 23 and comprises an endless chain or belt such as is employed'in a chain grate stoker. The conveyor 1 is con tained' within a furnace structure 4, the roof 5 of which slopes upwardly towards its front and in transverse section is of curved formation. The space between the roof 5 and the conveyer l constitutes a combustion chamber. The lower part of the structure 4: constitutes an ashpit 6 which contains water and is sealed at its rearward end by the rear end wall of the furnace structure/ The ashes and clinker are withdrawn from the ashpit 6 underneath the rear end wall of the furnace structure 4;. The shafts 23 extend from back to front ofthe furnace structure 4 andare' carried in pedestal or similar bearings 7 which are mounted on girders 8 disposed parallel to the shafts23 and constituting a part of a conveyor carrying structure hereafter dcs'cribed. Theshaft 3 extends through the front wall of the furnace structure 4 and "external thereto carries a chain wheel or pulley 9 that is driven by a chain or belt 1O operatively connected to a chain wheel or pulley 11. The chain wheel or pulley 11 gearing 12, the primary shaft of which is driven by; an'electric motor 13. Insideof the furnace the 'shafts 2 -3 carry chain or sprocket wheels 14 which mesh with the conveyor 1, the chain or sprocket wheels 14 on the shaft 3' driving the conveyor. The direction of rotation imparted to the shaft 3 issuch that the upper part of the conveyor, which constitutes a fuel bearer, is

maintained taut. Owing to the disposition of the shafts 2, 3, the direction of travel of the conveyor 1 is across or transverse to the longitudinal axis of the furnace structure 4.

The girders 8 are carried at their ends in frames and are also supported at an intermediate part by a frame 16. The frames 15 extend higher than the frame 16 and the lower part of each of the frames 15, 16 is arcuate. The frames 15-16 are connected together by longitudinal members 17, 18 which are secured thereto in such wise that they are in a plane which is above that containing the girders 8 and are very widely spaced apart. The structure constituted by the frames 1516, girders S and longitudinal members 17-18 is covered, as to its lower part, by sheet metal 19 which is secured, as to two of its edges, to the frames 15, and, as to its other edges, to the outer sides of the longitudinal members 17-18. The sheet metal covering 19 is also secured to the frame 16.

From the foregoing description and from the drawings, it will be seen that the conveyor is, in effect, jacketed, the one wall of the jacket being formed by the upper part of the conveyor.

20' are openings formed through the sheet metal covering 19. These openings are surrounded. by trunkings 21 which depend into the water contained in the ashpit and are sealed thereby. 22 are rollers mounted in the lower part of the furnace structure 1. These rollers carry the conveyorcarrying structure described and permit it to be i'noved angular-1y. The longitudinal mem- ,bers 1718'are of unlike construction. The longitudinal member 17 has, on its inner side or edge, an upstanding flange 23 and a depending flange 24., The upstanding flange 23 serves to support a member 25, which is of the same length as the member 17 and has along its upper portion a hook portion to engage the flange. The member 25 rests on the upper part of the conveyor 1 and is of such dimensions that it assumes v a position at right angles, or approximately ,side of the longitudinal member 18 is formed so as to be engaged pivotally by a member 27 which is of the same length as the member 18 and rests upon the conveyor, assuming an inclined attitude in relation thereto.

The members 25 27 extend longitudinally of the conveyor and constitutes walls to limit the fuel bearing area.

28-29 are members mounted on the front and rear f'ames 15 respectively. These members, which are of differentheights, constitute walls to enclose the front and back side-s or edges of the conveyor 1. 30 is a fuel supply chute positioned above the wall 28, and 31 is a duct adjacent the chute 30 through which the flames and products of combustion pass to the apparatus to be heated thereby. 32 is a fan which is driven by the electric motor 13 already referred to. The discharge outlet of the fan is connect ed by a duct 33 with the front end of the jacket of the conveyor 1, the duct 33 being of such formation that it will not interfere with the angular movement of the conveyor and its jacket. The fuel is supplied to the conveyor 1 through the chute 30 and travels along the conveyor while undergoing combustion, the ashes and clinker being discharged at the other side or edge of the conveyor over the wall 29 into the chute 3 in communication withthe ashpit- 6. The wall 28 being higher than the wall 29, and the lower end of the ch'ute'30 above the wall 28, the fuel is supplied to the conveyor at a higher level than that at which the ashes and clinker are discharged. The conveyor is positioned so that the fuel bearer portion is inclined to the horizontal, as shown in Figure 2, and the travel of the fuel along the conveyor is due to the differences in level of the points at which the fuel is supplied to the conveyor and the ashes and clinker are discharged therefrom, and also to the lifting of the fuel from a lower to a higher level by the conveyor and its backward fall when the angle of repose is exceeded.

The air supplied by the fan 32- passes into the jacket of the conveyor and to the bed of fuel through the fuel bearer portion of the conveyor, as indicated by the arrows in Figure 1. The passage of fuel from one sideor edge of the conveyor to the other is controlled by the rate at which the fuel is convey-ed to the conveyor through the chute 30 and the depth of the fuel on the fuel bearer portion of the conveyor'is regulated and controlled by the heights of the wall 29.

The walls 25-27 are of suflicient height to prevent passage of fuel thereover.

In the modification illustrated in Figure 5, the fuel bearer portion of the conveyor instead of being taut is of trough or channel shape, and, to attain this shape, the

shafts 23 are both driven, in which case,

they are driven synchronously, or only the shaft 2 is driven, in which case, its direction of rotation is such as to tend to cause or assist in causing the conveyor 1 to assume the trough or channel shape. The trough or channel shape is inclined transversely of its length so that the fuel when delivered thereto through the chute 30 is lifted from a lower to a higher level and is kept in a constant state of agitation due to its backward fall when the angle of repose is exceeded.

It will be seen that in the two arrangements described, the inclination or slope of the fuel bearing portion of the conveyor may be altered to suit different fuels. Further, the conveyor or belt may be so mounted that it slopes from front to back of the'furnace structure 4, or it may be horizontal as shown.

I claim:

1. A furnace structure comprising an endless fuel conveyor mounted in an inclined position in the furnace, means for feeding fuel onto the conveyor at one side thereof, means for causing movement of the conveyor to convey the fuel in an upward direction, and a clinker and ash take-off chute at the side of the conveyor opposite the fuel feed.

2. The-construction defined in claim 1,.

wherein the conveyor is mounted on shafts, and means forrotating one of the shafts to drive the conveyor and to maintain the desired shape of the top surface of the conveyor.

3. The construction defined in claim 1, wherein the conveyor is moiuited within a housing which is supported on rollers, and means for causing travel of the conveyor.

4. The construction defined in claim 1, wherein the conveyor is contained in a housing which is closed below the upper or fuel carrying portion of the conveyor, and in which said housing is perforated to permit passage of air therethrough, in combination with means for passing air through said structure and through the fuel on the conveyor. 1

5. A furnace structure comprising an endless. fuel conveyor mounted in an inclined position in the furnace, means .for driving the fuel bearing portion of said conveyor in an upward direction, means for supplying fuel at one side of said conveyor, an ash and clinker receiver at the other side of said conveyor, a combustion chamber, and means for passing air through the conveyor in a direction towards the combustion chamber.

6. A furnace structure comprising an endless fuel conveyor mounted in an inclined position in the furnace, means for driving the fuel bearing portion of said conveyor in an upward direction, a perforated housing enclosing the lower portion of said cone veyor, means for feeding fuel to one side of the upper portion of said conveyor, an ash discharge chute at the other side of said con veyor, a combustion chamber, and means for passing air through the perforations in said housing in a direction towards said com bustion chamber.

In testimony whereof I have signed my name to this specification.

JAMES STANLEY ATKINSON; 

